The contest comes on the back of research that showed a 46% increase in UK holidaymakers searching for single night holidays or "nanobreaks" over the past year.
In keeping with the nano theme, participants must create a micro blog about their break either as a series of Twitter posts, photos using Flickr or on video via YouTube. The posts will be streamed live from the social media sites.
Whoever posts the best entry will win an extended break to Rio de Janeiro in Brazil for two, courtesy of Tap Portugal and the Caesar Park Ipanema hotel. Three runners up with each receive one £200 Hotels.com voucher.
Alison Couper, communications director for Hotels.com, said: "All of our research shows that people see holidays as a right not a luxury and the rise in searches for nanobreaks is further evidence of holidaymakers' determination to keep travelling.
"We hope this competition will reward that determination with a bit of creative fun and encourage more people to take a much needed break."
The competition, which is open to UK residents over 18, closes on September 1st 2009. Details can be found on Hotels.com's website.